Finding the Fourth Proportional to 2,143.65, 2,958.18 and 1,212.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,143.65 : 2,958.18 = 1,212.15 : x
2. Step 2: Convert to fraction form
   2,143.65/2,958.18 = 1,212.15/x
3. Step 3: Cross multiply
   2,143.65x = 2,958.18 × 1,212.15
4. Step 4: Simplify right side
   2,143.65x = 3,585,757.89
5. Step 5: Solve for x
   x = 3,585,757.89/2,143.65
6. Step 6: Final answer
   x = 1,672.73